/*
 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import org.testng.ITestResult;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.CharArrayReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.io.PipedReader;
import java.io.PipedWriter;
import java.io.PushbackReader;
import java.io.Reader;
import java.io.StringReader;
import java.io.UncheckedIOException;

import static org.testng.Assert.assertEquals;

/*
 * @test
 * @bug 8029689
 * @summary checks the bounds part of the contract of java.io.Reader.read(char[], int, int):
 *
 *              0 <= off <= off+len <= cbuf.length
 *
 *          for publicly exported subtypes of java.io.Reader
 *
 * @run testng ReaderBulkReadContract
 */
public class ReaderBulkReadContract {

    @DataProvider(name = "readers")
    public Object[][] createReaders() throws IOException {
        return new Object[][]
                {
                        {new BufferedReader(new StringReader(""))},
                        {new BufferedReader(new StringReader("abc"))},
                        {new LineNumberReader(new StringReader(""))},
                        {new LineNumberReader(new StringReader("abc"))},
                        {new CharArrayReader(new char[]{})},
                        {new CharArrayReader(new char[]{'a', 'b', 'c'})},
                        {new InputStreamReader(new ByteArrayInputStream(new byte[]{}))},
                        {new InputStreamReader(new ByteArrayInputStream(new byte[]{'a', 'b', 'c'}))},
                        {newFileReader("")},
                        {newFileReader("abc")},
                        {new PushbackReader(new StringReader(""))},
                        {new PushbackReader(new StringReader("abc"))},
                        {newPipedReader("")},
                        {newPipedReader("abc")},
                        {new StringReader("")},
                        {new StringReader("abc")},
                };
    }

    @Test(dataProvider = "readers", expectedExceptions = IndexOutOfBoundsException.class)
    void off_negative_len_zero(Reader r) throws IOException {
        r.read(new char[8], -1, 0);
    }

    @Test(dataProvider = "readers", expectedExceptions = IndexOutOfBoundsException.class)
    void off_negative_len_positive(Reader r) throws IOException {
        r.read(new char[8], -1, 1);
    }

    @Test(dataProvider = "readers", expectedExceptions = IndexOutOfBoundsException.class)
    void len_negative(Reader r) throws IOException {
        r.read(new char[8], 0, -1);
    }

    @Test(dataProvider = "readers", expectedExceptions = IndexOutOfBoundsException.class)
    void integer_overflow(Reader r) throws IOException {
        r.read(new char[8], 4, Integer.MAX_VALUE);
    }

    @Test(dataProvider = "readers", expectedExceptions = IndexOutOfBoundsException.class)
    void off_plus_len_greater_than_buffers_length(Reader r) throws IOException {
        r.read(new char[8], 5, 4);
    }

    @Test(dataProvider = "readers")
    void subarray_N_0(Reader r) throws IOException {
        int read = r.read(new char[8], 8, 0);
        assertEquals(read, 0);
    }

    @Test(dataProvider = "readers")
    void subarray_8_0_0(Reader r) throws IOException {
        int read = r.read(new char[8], 0, 0);
        assertEquals(read, 0);
    }

    @Test(dataProvider = "readers")
    void subarray_0_0_0(Reader r) throws IOException {
        int read = r.read(new char[0], 0, 0);
        assertEquals(read, 0);
    }

    @AfterMethod
    void close(ITestResult r) throws IOException {
        Reader reader = (Reader) r.getParameters()[0];
        reader.close();
    }

    private static FileReader newFileReader(String contents) {
        try {
            File f = File.createTempFile("ReaderContract", "");
            try (FileWriter w = new FileWriter(f)) {
                w.write(contents);
            }
            return new FileReader(f);
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }

    private static PipedReader newPipedReader(String contents) throws IOException {
        try (PipedWriter w = new PipedWriter()) {
            PipedReader r = new PipedReader(w);
            w.write(contents);
            return r;
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }
}